Shiori

Biodata

Feature	Details
Name	Shiori Itsuka (士织)
Species/Race	Human with a unique Spirit-sealing constitution 66
Gender	Female
Occupation/Role	High-school student; key participant in the plan to seal Spirits’ spiritual power 66
First Appearance	Chapter 65 65

Background / History

Five years before her introduction, Shiori sealed the spiritual power of her younger sister, Kotori, during the fire caused by Kotori’s birth as the Fire Spirit. Shiori lost her memories of the event afterward and continued living as an ordinary student, unaware of Spirits, Spatial Quakes, or her own role in preventing them. 65

Despite being only sixteen, Shiori balances school and club activities with much of the Itsuka household’s cooking, shopping, cleaning, and other domestic work. Her home life with Kotori is notably warm and close. 65 66

Kotori eventually reveals the truth about Spirits, Ratatoskr’s research into Shiori’s ability, and the Spirit-sealing plan. After being told that she alone can seal spiritual power and prevent Spatial Quakes at their source, Shiori chooses to participate of her own will. 66

Appearance

Shiori is a slender blue-haired girl whose lively, innocent expression contrasts with the composed presence Kotori displays as Fraxinus’s commander. She is described as exceptionally attractive, with a gentle, traditional-beauty-like aura. 65 67 91

• Blue hair 65
• Slender build 67
• Popular at school due to her appearance, strong grades, and friendly disposition 91
• Usually wears a school uniform during her daily life 91

Personality

Shiori is sunny, gentle, and deeply protective of the people close to her, particularly Kotori. She is willing to shoulder responsibilities that frighten or overwhelm her, but she does not treat that responsibility as permission to disregard a Spirit’s feelings. Her decision to help Seven Deadly Sins despite the latter’s hostility reflects her desire to understand others before judging them. 66 96

Having lived as an ordinary student, Shiori initially lacks combat knowledge and becomes uneasy when confronted with the reality of Spatial Quakes and Spirit battles. Nevertheless, seeing Tohka’s loneliness turns her participation in the sealing plan from a duty into a personal commitment. 67 69

Shiori is wary of Ratatoskr because of its long-term observation and research of her without her informed consent. She increasingly favors Schicksal’s protection after Yulande repeatedly treats her as someone entitled to make her own choices. 70 72 81

Abilities & Skills

Spirit Power Sealing

Shiori possesses a unique constitution capable of sealing a Spirit’s spiritual power, thereby preventing the Spatial Quakes caused by that Spirit’s manifestation. The exact reason only she possesses this ability remains unknown despite Ratatoskr’s research. 66

• The sealing method requires making the Spirit blush, then kissing them. 66
• Shiori previously sealed Kotori’s power as a child, though she lost the memory afterward. 65
• She later becomes Tohka’s sealer and assumes responsibility for her well-being. 79 92
• Her ability makes her a central target for Ratatoskr, Schicksal, and DEM. 90 92

Regenerative Ability

Shiori has powerful regenerative capabilities associated with her special constitution. 79 80

• A penetrating abdominal wound healed completely within three minutes. 79
• Her recovery does not make her immortal; Kotori warns that a hostile Spirit could still kill her. 96

Spirit Communication

Though inexperienced, Shiori can form connections with Spirits through directness and empathy rather than force. Her first contact with the unnamed Princess succeeds because she recognizes the Spirit’s grief and approaches her sincerely. 67

• She helps the Princess understand the destruction caused by her manifestations without condemning her. 70
• Exchanging names with the Princess begins their mutual understanding and friendship. 69 70
• She remains determined to contact Seven Deadly Sins even after learning that the Spirit had targeted her. 96

Relationships

• Kotori Itsuka — Younger sister. Shiori cared for Kotori without knowing she was a Spirit or Fraxinus commander; their relationship becomes strained but more honest once Kotori reveals the truth. 65 66
• Tohka Yatogami — First Spirit Shiori approaches after accepting the sealing plan. They become close friends, and Tohka regards Shiori as one of the few humans worth protecting. 67 70 80
• Bianca “Yulande” Atagina — Friend and protector. Yulande insists Shiori has the right to choose her own life, helps protect Tohka, and arranges a Valkyrie bodyguard for Shiori. 66 80 90 91
• Shier Fulei — Schicksal Valkyrie assigned as Shiori’s school bodyguard under the guise of a transfer student. Shiori welcomes and protects her from overwhelming attention at school. 91
• Seven Deadly Sins — A hostile Spirit who impersonates Shiori and threatens to ruin her life. Despite this, Shiori wants to learn why she is hated and attempt contact rather than reject her outright. 90 92 96
• Ratatoskr — The organization that researched Shiori’s constitution and relies on her for its Spirit-sealing plan. Shiori distrusts its treatment of both herself and Kotori. 66 70
• Schicksal — An alternative protector for Shiori and the sealed Spirits. Shiori’s trust in Yulande leads her and Kotori to consider joining Schicksal and placing the Spirit-sealing plan under its authority. 71 99

Story Role / Major Arcs

Revelation of the Spirit-Sealing Plan

Shiori learns that Kotori was once the Fire Spirit and that her own forgotten childhood sealing is Ratatoskr’s sole proof that Spirits can be safely sealed. Given the choice rather than an order, she agrees to become the plan’s central participant. 65 66

First Contact with Tohka

Accompanied by Amber, Shiori enters the ruins created by a Spirit manifestation and approaches the being known as the Princess. Moved by the Spirit’s sorrow, she begins communicating with her instead of treating her as a target. 67

Shiori and the Princess exchange names, with the Princess becoming Tohka. Shiori explains why Tohka’s manifestations harm humans and offers sealing as a way for her to live without causing destruction. 69 70

Distrust of Ratatoskr

While participating in Ratatoskr’s plan, Shiori grows uncomfortable with the organization’s secrecy, its research of her body, and its influence over Kotori. She instead views Yulande and Schicksal as more trustworthy protectors for herself and Tohka. 70 72 81

DEM Targeting and Protection

After Seven Deadly Sins threatens her, Shiori becomes a target of DEM’s attempt to hinder Schicksal. Kotori requests Schicksal’s help, leading to Shier Fulei’s transfer into Shiori’s class as a bodyguard. 90 91 92

Contacting Seven Deadly Sins

Seven Deadly Sins impersonates Shiori to manipulate Tohka and is later revealed to have been actively hostile toward Shiori. Even after this, Shiori decides that she wants to understand the Spirit’s motives and seek contact, though Kotori cautions her not to meet the Spirit alone. 92 96

Notable Quotes

“If this is something only I can do, then I have no reason not to.” 66